Memory & Cognition 1998,26 (2),287-298 Prospective memory: When reminders fail MEUSSAJ. GUYNN and MARK A. McDANIEL University ofNew Mexico, Albuquerque, New Mexico and GILLES O. EINSTEIN Furman University, Greenville, South Carolina A frequent assumption in the area of prospective memory is that a reminder to do an activity in the future improves the likelihood of doing the activity. The results of four experiments indicated, however, that the most general version of this assumption is incorrect. Subjects were either reminded of a prospective memory task several times during a retention interval or not reminded of the prospective memory task. The most effective reminders referred both to the prospective memory target events and to the intended activity.Reminders that referred only to the target events did not improve prospective memory (relative to a no-reminder control). Reminders that referred only to the intended activity did improve prospective memory, but not to the level of reminders that referred both to the target events and to the intended activity.Instructions to imagine oneself performing the prospective memory task did not further improve prospective memory. Neither the delay between the prospective memory in­ structions and the prospective memory cover task nor the delay between a reminder and a prospective memory target event significantly influenced performance. The results, which are discussed in terms of theoretical and practical implications, supporta new theory of prospective memory and suggest sur­ prising conditions under which reminders fail to benefit prospective memory. When one thinks ofremembering, at least two senses of simulate real-world prospective memory tasks in which the word come to mind. A person can remember infor­ people are busily engaged in activities (e.g., working on mation learned in the past, which is often referred to as a manuscript) that they must remember to interrupt at an retrospective memory. Thus a person can remember the appropriate point in order to do another intended activity contents ofa book, what he or she did last night, or a list (e.g., give a colleague a message). After the instructions ofwords learned in a memory experiment. A person can for the cover task, subjects are then given the instructions also remember to do an activity in the future, which is gen­ for the prospective memory task. This often involves ask­ erally referred to as prospective memory. For instance, a ing the subjects to do something (e.g., press a key) when­ person can remember to give a friend a message, to keep ever they see a particular word in the context ofthe cover an appointment, or to press a key when a target word ap­ task (Einstein, Holland, McDaniel, & Guynn, 1992; Ein­ pears in a memory experiment. Despite the prevalence of stein & McDaniel, 1990; McDaniel & Einstein, 1993).Fol­ both types ofmemories in everyday life, only retrospective lowing the instructions for the prospective memory task, memory has been extensively studied, and we therefore one or more intervening tasks are presented, to discour­ know comparatively little about prospective memory. age continuous maintenance ofthe prospective memory In recent research on prospective memory, the follow­ instruction throughout the experiment. Finally, the cover ing paradigm has generally been used. Subjects are first activity is presented, with no mention ofthe prospective given instructions for what they think is the primary task memory task, and subjects' success at remembering to per­ ofthe experiment. The prospective memory task is em­ form the prospective memory task is assessed. bedded within this "cover" activity. This is intended to Initial investigations ofprospective memory with this type of paradigm have focused on characteristics ofthe prospective memory target events that indicate that it is This research was supported in part by a National Science Foundation appropriate to perform the intended activity. For exam­ Graduate Research Fellowship to M.1.G., National Institute on Aging ple, the familiarity, distinctiveness, and typicality ofthe (NIA) Grant AG05627 to M.A.M., and Grant AF 49620-92-1-0437 from target words have been found to affect prospective mem­ the Air Force Office of Scientific Research to Henry L. Roediger III. ory (Brandimonte & Passolunghi, 1994; Einstein & Me­ In addition, preparation of this article was supported in part by NIA Grant AG08436 to G.O.E. and M.A.M. We are grateful to Betty Glisky Daniel, 1990; Mantyla, 1993, 1996; McDaniel & Einstein, for the use of her laboratory facilities at the University ofArizona, and 1993). Other investigations have focused on subject dif­ to Scott Newberger, Ellie Corbett, and Barbie Brogan for testing subjects ferences (primarily age differences) in prospective mem­ in Experiment 3. Correspondence concerning this article should be ad­ ory (Einstein et aI., 1992; Einstein & McDaniel, 1990;Ein­ dressed to M. 1.Guynn at the Department ofPsychology, University of stein, McDaniel, Richardson, Guynn, & Cunfer, 1995; New Mexico, Albuquerque, NM 87131 (e-mail: [email protected]). Goschke & Kuhl, 1993, 1996; Maylor, 1990; McDaniel, -Accepted by previous editor, Geoffrey R. Loftus Glisky, Rubin, Guynn, & Routhieaux, 1998). 287 Copyright 1998 Psychonomic Society, Inc. 288 GUYNN, McDANIEL, AND EINSTEIN There has been much less focus on the effect ofactiv­ tation is unclear. Increased thinking about the task might ities or events occurring during the interval between the lead to better prospective memory, or better prospective prospective memory instructions and the opportunity for memory might lead to increased thinking about the task, performance of the prospective memory task (i.e., during or a third factor might be responsible for both. Meacham the delay or retention interval). One such factor that and Leiman (1982) provided more direct evidence by ex­ would seem to affect prospective memory substantially perimentally manipulating reminders. Providing subjects is the presence of reminders. Although she did not specif­ with a colored tag for their key chains produced a mod­ ically mention reminders, Ellis (1996) proposed that rec­ est increase in promptly returning postcards to the ex­ ollections, prompted either by oneselfor by another per­ perimenter (relative to not providing such a reminder), but son, might affect prospective memory. According to Ellis, this effect was observed in only some conditions. a recollection refers to remembering a delayed intention Two recent studies urge caution in assuming benefits before the occurrence ofa retrieval context during a per­ ofreminders to prospective memory. Goschke and Kuhl formance interval. In our terms, the delayed intention is (1993, 1996) investigated prospective memory as a func­ the intended activity, the retrieval context is the appear­ tion ofwhether their subjects were state oriented or ac­ ance ofa target event, and the performance interval is the tion oriented. State-oriented individuals experience more cover task activity.Thus Ellis's view on the function ofrec­ involuntary thought intrusions about future goals than do ollections could be considered to apply to reminders as action-oriented individuals. State-oriented individuals well. According to her view, such recollections might are therefore thought to be more likely to maintain an ac­ improve prospective memory by refreshing or strength­ tive representation of a future task in mind, whether or ening the prospective memory representation (e.g., by not they expect the future task to be prompted by external increasing its activation level) or by reformulating or al­ cues. Action-oriented individuals are thought to main­ tering the prospective memory representation (e.g., by tain an active representation ofa future task in mind only increasing the specificity ofthe retrieval context). when they do not expect to be prompted by external cues. Mantyla (1996) proposed that activities directed at plan­ State-oriented and action-oriented subjects did not differ ning the prospective memory task might affect prospective in prospective memory, leading Goschke and Kuhl to memory. According to his view, the planning ofactivities conclude that continuous activation ofan intention in ex­ might improve prospective memory by automatically in­ plicit memory is not necessary for its execution (when ex­ creasing the activation level ofthe prospective memory ternal retrieval cues are available). Because there was no representation, or by creating a more complex or detailed difference in prospective memory between a condition representation that could benefit prospective memory by with presumably few or no self-reminders (action-oriented increasing the number ofpotential retrieval routes. In our subjects) and a condition with presumably many more self­ view, it seems that reminders might provide the oppor­ reminders (state-oriented subjects), the results suggest that tunity either for constructing a plan, or for reviewing or reminders do not benefit prospective memory. updating an existing plan. This is consistent with Man­ In line with this suggestion, Vortac, Edwards, and Man­ tyla's (1996) proposal that one's self-initiated activities ning (1995) found that providing cues continuously dur­ while one is doing another task (such as asking oneself ing a retention interval (to support rehearsal) did not what one is supposed to remember) might increase the produce better prospective memory relative to a control activation level ofthe prospective memory representation. condition